Benzoxazolylstilbenes



United States Patent 1 3,407,196 BENZOXAZOLYLSTILBENES Peter Liechti, Binningen, Erwin Maeder, Aesch, Basel,

Leonardo Guglielmetti, Birsfelden, Max Duennenberger, Frenkendorf, and Adolf Emil Siegrist, Basel, Switzerland, assignors to Ciba Limited, Basel, Switzerland, a Swiss company No Drawing. Continuation-impart of application Ser. No. 408,756, Nov. 4, 1964. This application Sept. 1, 1967, Ser. No. 664,899 Claims priority, application Switzerland, Nov. 14, 1963, 13,986/63; May 12, 1964, 6,155/64 12 Claims. (Cl. 260-240) ABSTRACT OF THE DISCLOSURE The present invention concerns new bis-(benzoxazolyl- 2)-4,4-stilbenes, which contain in the benzene ring of the benzoxazolyl residue a carboxyl group in free form, esterified or as nitrile group, and wherein the ethylene bridge member of the stilbene moiety is unsubstituted. These new compounds represent valuable optical brighteners, especially for aromatic polyesters and for polyamides.

Cross-references to related applications This is a continuation-in-part of application Serial No. 408,756, filed November 4, 1964, now abandoned.

The present invention provides new, valuable bisbenzoxazolyl-stilbenes of the formula wherein U represents a member selected from the group consisting of hydrogen and N U /N\\\C CH=CH C (1 Q Q V wherein U represents a member selected from the group consisting of hydrogen and Y and Y is a member selected from the group of consisting of a carboxyl group, a carbalkoxy group having 1 to 18 carbon atoms in the alkoxy group, a carboxylic acid allyl ester group an a COO-(C -C,)-alkyleneO-alkyl(C -C group.

Within the scope of the foregoing formulae there are of preferred interest compounds of the formula (3) 3,407,196 Patented Oct. 22, 1968 wherein Y is a member selected from the group con sisting ot a carboxyl group, a carbalkoxy group, having from 1 to 6 carbon atoms in the al-koxy group a carboxylic acid allyl ester group and a C$)O-(C -C )-alkylene- O-alkyl(C C group.

The new bis-oxazolyl-stilbene compounds of the Formula 1 can be manufactured by various, for example as such known, methods.

According to one process, for example, at least one ortho-hydroxyamino compound is reacted at an elevated temperature, for example at to 330 C., with or without intermediate isolation and preferably in the presence of a catalyst, in the molecular ratio of 2:1 with stilbene-4,4-dicarboxylic acid or with a functional derivative of this dicarboxylic acid, especially an ester such as diethyl ester or an acid halide such as the acid chloride, using an ortho-hydroxyamino compound of the formulae where U T Y and n have the meanings defined above.

The reaction of the selected componentscan be performed with or without intermediate isolation by heating at an elevated temperature, for example from 120 to 330 C., advantageously in an inert gas, for example nitrogen, and if necessary'or desired inthe presence of a catalyst. Suitable catalysts are, for example boric acid, zinc chloride, paratoluenesulfonic acid, also polyphosphoric acids including pyrophosphoric acid. When boric acid is used as catalyst, it is of advantage to use it in an amount from about 0.5 to 5% referred to the weight of the reaction mixture as a whole. There may also be used additionally high-boiling, polar, organic solvents such, for example, as dimethyl formamide, and aliphatic (optionally etherified) hydroxy compounds, for example dialkylcarbitols, propyleneglycols, ethyleneglycol monoethyl ether or diethyleneglycol diethyl ether and high-boiling esters of phthalic acid, for example phthalic acid di butyl ester.

Alternatively, a two-stage variant may be used, wherein first 1 mol of a stilbene-4,4'-dicarboxylic acid or of a functional derivative thereof, especially 1 mol of the dicarboxylic acid dichloride, is reacted with 2 mob of the ortho-hydroxyamino compound in the presence of an organic solvent such as toluene, a xylene, chlorobenzene, di-

chloro-benzene or nitrobenzene, at an elevated temperature, whereupon the acyl compound obtained in this manner is converted into the bis-oxazolyl-stilbene at an elevated temperature, if required or desired in the presence of a catalyst. When the starting material to be used is a dicarboxylic acid dichloride, it can be prepared directly, prior to the condensation with the ortho-hydroxyamino compound and without isolation, from the free dicarboxylic acids and thionyl chloride in the solvent in which subsequently the condensation is carried out.

In the dissolved or finely dispersed state the new bisoxazolyl-stilbene compounds of the composition defined above display a more or less strongly pronounced fluorescence. They may be used for optically brightening a wide variety of organicmaterials. Good results are obtained, for example, in brightening acryl resin lacquers, alkyd resin lacquers, cellulose ester lacquers, for example acetylcellulose lacquers or nitrocellulose lacquers. The new bisoxazoles are particularly suitable for optically brightening synthetic fibers, for example from cellulose esters, cellulose propionate or acetylcellulose (cellulose diacetate or cellulose triacetate; acetate rayon), especially from polyamides (for example nylon) and polyesters, from polyolefines such as polyethylene, and films, foils, tapes or mouldings from these materials or from other materials, such as polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol or polyvinyl esters of organic acids, for example polyvinyl acetate, and finally those from regenerated cellulose, including spun rayon. The new bis-oxazoles can also be used for brightening natural fibers, for example cotton or wool fibers.

If the optical brightening according to this invention is to be applied to fiberswhich may be staple fibers or monofils, in the crude state, in the form of hanks or woven fabrics-this is advantageously achieved in an aqueous medium in which the brightening substance is suspended. If required or desired, the treatment may be performed in the presence of a dispersant, for example soaps, polyglycol ethers of fatty alcohols, fatty amines or alkylphenols, cellulose sulfite waste liquor or formaldehyde condensation products of (option-ally alkylated) naphthalene-sulfonic acids. Particularly good results have been obtained by working in a neutral, weakly alkaline or acid bath. It is likewise advantageous to perform the treatment at an elevated temperature ranging from about 50 to 100 C., for example at the boiling temperature of the bath or in its neighbourhood (about 90 C.). The improving treatment of this invention may also be performed with solutions in organic solvents.

The new bis-oxazoles to be used according to this inr vention may also be added to or incorporated with the materials before or during their shaping. Thus, in the manufacture of films, foils, tapes or mouldings they may be added to the moulding composition or dissolved or finely dispersed in the spinning composition before spinning it. The new brighteners may also be added to the reaction mixtures before or during the polycondensation leading, for example, to polyamides or especially polyesters, or before or during the polymerization of monomers, for example vinyl acetate or styrene, to the polymer masses.

The new 'bis-oxazoles are distinguished by their particularly good thermostability, fastness to light and to migration.

The amount of new bis-oxazole to be used according to this invention, referred to the weight of the material to 4 be optically brightened, may vary within wide limits. Even a very small amountin certain cases, for example, as little as 0.005%may suflice to produce a distinct and lasting effect, though an amount of up to about 0.5% or even more may be used just as well.

The new bis-oxazoles to be used as brighteners may also be used in the following ways:

(a) In admixture with dyestuifsor pigments or as additives to dyebaths, printing inks, discharge or reserve pastes. Furthermore, also for after-treating dyeings, prints or discharge prints.

(b) In admixture with so-called carriers, antioxidants, light filters, heat stabilizers, chemical bleaches or as additives to bleaching baths.

(c) In admixture with dressing agents, such as starches or synthetic dressing agents. The products of this invention may also be used with advantage for producing a creaseresisting finish by being added to liquors used for this purpose.

' (d) In combination with detergents. The detergent and the brightener may be added separately to the washing liquor. It may also be of advantage to use a detergent that as such already contains a proportion of brightener. Suitable detergents are, for example, soaps, salts of sulfonate detergents, for example of sulfonated benzimidazoles substituted on the carbon atom 2 by higher alkyl radicals; also salts of monocarboxylic acid esters of 4- sulfatophth-alic acid with higher fatty alcohols; furthermore salts of fatty alcohols; furthermore salts of fatty alcohol su'lfonates, alkylarylsulfonic acids or condensation products of higher fatty acids with aliphatic hydroxysulfonic or aminosulfonic acids. Likewise suitable are non-ionic detergents, for example polyglycol ethers derived from ethylene oxide and higher fatty alcohols, alkylphenols or fatty amines.

If the present process is combined with other treating or improving operations, the combined treatment is advantageously performed with the aid of a suitable preparation. These stable preparations contain compounds of the above Formula 1 as well, as dispersants, detergents, carriers, dyestuffs, pigments or dressing agents.

The compounds of the above Formula 1 may also be fixed on a finely dispersed support and used in this form. They are also suitable for use as scintillators, for various photographic purposes, such as for electrophotographic reproduction, or for supersensitizing.

Unless otherwise indicated, parts and percentages in the following examples are by weight.

Example 1 3.59 parts of the compound of the formula and 1.67 parts of 1-hydroxy-Z-amino-S-carbomethoxybenzene in 60 parts by volume of dichlorobenzene are stirred under reflux with exclusion of air and moisture. 20 parts by volume of dibutylphthalate are then added and the mixture is heated to 330 C. while distilling off dichlorobenzene and the water of reaction. After cooling to room temperature (about 20 C.), suctioning, washing with ethanol and drying, there are obtained 4.0 parts of the compound of the formula OCH:

Yellow, crystalline precipitate from dichlorobenzene, melting above 305 C.

C H O N Calculated C, 76.26%; H, 4.27%; N, 5.93%. Found C, 76.20% H, 4.39%; N, 6.04%.

In analogous manner the compounds of the following formulae are obtained:

Small, light-yellow needles, from dioxane, melting above 310 C.

C H O N Calculated C, 77.87%; H, 6.01%; N, 4.91%. Found C, 78.04%; H, 6.09%; N, 5.25%.

Small, yellow needles from chlorobenzene, melting above 340 C.

C H O N Calculated C, 79.64%; H, 4.53%; N, 8.99%. Found C, 79.39%; H, 4.66%; N, 9.01%.

The acid chloride used as starting materials is manufactured in the following manner:

A solution of 324 parts of stilbene-4,4'-dicarboxylic acid diethyl ester in a mixture of 1000 parts by volume of ethanol and 4000 parts by volume of di-oxane is mixed at 40 C. with 100 parts by volume of N-sodium hydroxide solution. After stirring for one hour at 40 C., the resulting thick, cream-colored paste is cooled to room temperature (about C.), suctioned, washed with dioxane and thoroughly expressed. The moist filter cake is stirred for 2 hours in 10,000 parts by volume of 5% hydrochloric acid, suctioned and washed with water until the washings run neutral. The crude suction filter cake is stirred for 60 minutes in 2000 parts by volume of N-aqueous triethanolamine solution, and the undissolved matter is filtered off. The filtrate is acidified with concentrated hydrochloric acid, the precipitate formed is suctioned off, washed neutral and dried, to yield about 231 parts of the monocarboxylic acid of the formula as a colorless powder whose melting point depends substantially on the heating speed (230 to 300 C.).

C H O Calculated C, 72.96%; H, 5.44%; N, 21.60%. Found C, 72.75%; H, 5.40%; N, 21.34%.

When the above acid is boiled for 3 hours in excess thionylchloride, it gives a 97% yield of the acid chloride of the formula which from tetrachlorethylene forms colorless crystals melting at 134 to 136 C.

C H O Cl: Calculated C, 68.68%; H, 4.80%; N, 11.26%. Found 68.28%; H, 4.83%; N, 11.54%.

31.4 parts of the acid chloride (11) and 11.0 parts of Lhydroxy-Z-aminobenzene in 500 parts by volume of anhydrous ortho-dichlorobenzene are stirred at 15 hours at 136 C.; the dark solution is then mixed with 1 part of boric acid, heated to 180 C. While distilling off 300 parts by volume of water, and further stirred at this temperature for 2 hours.

After cooling, suctioning, washing with methanol and drying, there are obtained about 24.2 parts of the compound of the formula CHgCHa OCHzCHCHzCHzCHnCHa as a light-brown powder melting at 210 to 220 C. Recrystallization from tetrachlorethylene with the aid of bleaching earth furnishes a yellow, crystalline powder CHzCHaCN which melts at 227 to 229 C. and reveals the following analytical data:

C H O N: Calculated C, 78.03%; H, 5.18%; N, 3.79%. Found C, 78.33%; H, 5.27%; N, 3.75%.

39.6 parts of the ethyl ester (12) in 300 parts by volume of dioxane are hydrolyzed with 20 parts by volume of 10 N-sodium hydroxide solution for 4/ 12 hours at to C.; the batch is then mixed with parts by volume of methanol, then cooled to room temperature (about 20 C.), suctioned and washed with methanol. The moist suction filter cake is taken up in 1000 parts by volume of dimethylformamide, mixed at 100 C. with 40 parts by volume of concentrated hydrochloric acid, cooled, suctioned, washed and dried, to yield about 32.2 parts of the compound of the formula as a light-yellow powder melting at 318 to 320 C. On sublimation in a high vacuum at 285 C., light-yellow crystals of identical melting point are obtained.

C H O N: Calculated C, 77.40%; H, 4.43%; N, 4.10%. Found C, 77.30%; H, 4.60%; N, 4.18%. (Occasionally, the acid is obtained in a form that melts at.349 to 350 C.).

The oxazolecarboxylic acid (13) is converted in the known manner in a yield of about 87% into the acid chloride of the formula by boiling in an excess of thionylchloride in the presence of a catalytic amount of pyridine. Yellow crystals from orthodichlorobenzene, melting at 266 to 268 C.

C H O NCI: Calculated C, 73.44%; H, 3.92%; N, 3.89%. Found C, 73.42%; H, 4.04%; N, 3.86%.

Example 2 305 parts of powdered stilbene-4,4'-dicarboxylic acid chloride and 334 parts of 3-amino-4-hydroxybenzoic acid methyl ester are suspended in 2500 parts by volume of anhydrous dichlorobenzene. After having displaced the atmospheric oxygen from the apparatus by filling it with nitrogen, the batch is heated within about one hour to the reflux temperature while stirring it well. At 145 to 150 C. a strong evolution of hydrochloric acid sets in and is complete after refluxing for 4 hours. The whole is refluxed for 6 to 7 hours and then allowed to cool.

ish paste which is suctioned at room temperature, thoroughly expressed and rinsed with a small amount of methanol. To remove the dichlorobenzene the filter residue is suspended in 5000 parts by volume of methanol and heated at the boil for a short time, then suctioned at room temperature and rinsed with methanol. After drying, there are obtained about 533 parts of the compound of the formula /NH\ /HN CHaO (H) o H H 0 as a yellow-beige colored powder melting at 325 to 327 C. with decomposition.

500 parts of the above compound of the Formula 15 are stirred in 2000 parts by volume of phthalic acid dibutyl ester. The reaction mixture is then heated under nitrogen within minutes at 310 C., during which water escapes and a dark solution forms which is stirred 45 for about 5 minutes at 310 C. and then allowed to cool. At 100 C. 2000 parts by volume of methanol are run into the thickly liquid suspension; it is suctioned at room temperature and rinsed with methanol. The filter residue is then boiled for a short time with 5000 parts by volume of methanol, once more suctioned at room temperature and thoroughly rinsed with methanol and dried, to yield about 466 parts of a greenish yellow powder. After crysn N CIIaClIz C- tallization from dichlorobenzene with the use of bleaching earth it yields the compound of the formula 8 as a yellow, crystalline powder melting above 280 C.

C H N O Calculated C, 72.44%; H, 4.18%; N, 5.28%. Found C, 72.35%; H, 4.12%; N, 5.26%.

When 3-amino-4-hydroxybenzoic acid methyl ester is 5 replaced by 3-amino-4-hydroxybenzoic acid ethyl ester and the condensation is performed in identical manner, there is obtained the compound of the formula The reaction product at this stage forms a thick, yellowin approximately equal yield and purity from dichlorobenzene as a yellow, crystalline powder melting above 275 C.

C H N O Calculated C, 73.11%; H, 4.69%; N, 5.02%. Found C, 72.9%; H, 4.70%; N, 5.04%.

When the condensation referred to above is carried out OCH;

with 3-amino-4-hydroxybenzoic acid isopropyl ester, the compound of the formula is obtained from dioxane as a yellow, crystalline powder melting above 250 C.

C H N O Calculated C, 74.25%; H, 5.58%; N, 4.56%. Found C, 73.98%; H, 5.55%; N, 4.78%.

When the condensation referred to above is performed with 3 amino 4 hydroxybenzoic acid-(2-ethyl)-hexyl ester, the compound of the formula C Ii -CH3 O CH; C HCH2CH:CHzCI-Ia is obtained from dioxane as pale-yellow flakes melting above 240 C.

9 C H N O Calculated C, 76.00%; H, 6.93%; N, When the condensation is performed with 4-amino-3- 3.85%. Found C, 76.27%; H, 6.85%; N, 4.03%. hydroxybenzoic acid ethyl ester, the compound of the When the condensation referred to above is performed formula CHzCHg HsC-HzCO with 3-amino-4-hydroxybenzoic acid n-octadecyl ester, the is obtained from dichlorobenzene in the form of small,

product of the formula lemon-colored needles melting above 340 C.

(21) g l I? is obtained frorntoluerie as'a powder melting C L H O N Calculated C, 73.11%; H, 4.69%; N, above 240 C. 5.02%. Found C, 72.97%; H, 4.79%; N, 5.11%.

C H O N Calculated C, 78.69%; H, 9.00%; N, When the condensation is performed with 3-amino-4- 2.78%. Found C, 78.87%; H, 8.91%; N, 2.63%. hydroxybenzoic acid(2-methoXy)-ethyl ester, the com- When the condensation is performed with 3 amino-4- pound of the formula hydroitybenzoic acid allyl. ester, the compound of the is obtained from xylene as a yellow powder melting above formula 320 C.

(22) N I N u mo=o11omo r -oooH,oH=oH,

is obtained from dimethylformamide as a light-yellow C H N O Calculated C, 69.89%; H, 4.89%; N, powder melting above 270 C. 4.53%. Found C, 70.03%; H, 4.88%; N, 4.62%.

C H O N Calculated C, 74.21%; H, 4.50%; N, When the condensation is performed with 3-amino-4- 4.81%. Found C, 73.96%; H, 4.66%, N, 4.85%. hydroxy-S-methoxybenzoic acid methyl ester, the com- When the condensation is performed with 4-amino-3- pound of the formula 0 0 N N CH 0 C CH=CH 'C OCH I 3 3 i o 9 0 CH3 H;

hydroxybenzoic acid methyl ester, the compound of the is obtained from dichlorobenzene as a pale-yellow, granuformula I a lar precipitate melting above 350 C.

23) 1 l N i Y 0 i l N\ O o -CH=CH- -o -/C V \O CH30 00H,

is obtained from dichlorobenzene in the form of small, lemon-colored needles, melting above 320 C.

C H O N Calculated C, 72.44%; H, 4.18%; N, C H N O Calculated C, 69.14%; H, 4.44%; N, 5.28%. Found C, 72.20%; H, 4.21%; N, 5.30%. 4.74%. Found C, 68.82%; H, 4.45%; N, 4.98%.

3,407 ,196 l 1 1 2 4 Example 3 in the form of small yellow needles which melt at 350 C.

with decomposition.

5.1 parts of the dicarboxylic acid chloride of the Formula 29 are stirred with 2.5 parts of benzyl alcohol in 100 parts by volume of anhydrous chlorobenzene, mixed with 5 parts of pyridine, the whole is heated to reflux and maintained at this temperature for 4 hours, then allowed A solution of 54 parts of sodium hydroxide in 150 parts by volume of Water is added to a fine suspension of 77.4 parts of the compound of the Formula 16 in 1200 parts by volume of ethyleneglycol monomethyl ether. The batch 5 is then refluxed for 30 hours; the dark-yellow disodium salt of the formula is suctioned off at room temperature (about 20 C.) and rinsed thoroughly with methyl Cellosolve. To free the resito cool, suctioned, and the residue is thoroughly washed due from any residual starting material it is extracted with with acetone.

2000 parts by volume of boiling ortho-dichlorobenzene. 20 After drying, there are obtained about 5.8 parts of a After drying, there are obtained about 96 parts of a darkgreenish yellow powder which melts above 315 C. yellow, granular powder which does not melt up to Crystallization from chlorobenzene furnishes the com- 350 C. pound of the formula in the form of small, yellow needles which melt above The finely powdered disodium salt of the Formula 27 318 C.

is then suspended in 3000 parts by volume of boiling C44H3QO6N2: Calculated C, 77.40%; H, 4.43%; N, water, dilute hydrochloric acid is added to establish a 4.10%. Found C, 77.18%; H, 4.61%;N, 4.27%. strongly acidic reaction to Congo red and the whole is An analogous reaction of the dicarboxylic acidchloride refluxed for 1 hour and then allowed to cool, suctioned of the Formula 29 with 4-(l,1',3,3'-tetra-methyl-butyl)- at room temperature and washed with water until the phenol yields the compound of the Formula 31 (5113 CH; 3H: CH;

washings run neutral and dried. Yield: about 68.4 parts in the form of small, light-yellow needles, melting above of the dicarboxylic acid of the formula 340 C., from dichlorobenzene.

(2s) 0 o H0( i -ii-0H as a dark-yellow powder which does not melt up to C H O N Calculated C, 79.24%; H, 6.65%; N, 350 C. The compound is recrystallized from dimethyl- 3.19%. Found C, 78.84%; H, 6.68%; N, 3.29%. sulfoxide.

Example 4 Example 5 A suspension of 119.2 parts of the dicarboxylic acid of 290 parts of Powdered stilbene-4.4'-dicarboxylic acid the Formula 28 in 1500 parts by volume of chlorobenh r a 370 parts f 3 y yp y -p zene is mixed with 150 parts by volume of thionylchloride 60 P C 361d methyl ester are t r d in 7500 parts by nd 5 parts by v l m of dimethylformamide d the volume of anhydrous xylene at room temperature (about mixture is heated for 48 hours at to C., where- 18 C.). The atmospheric oxygen is displaced from the upon the evolution of hydrochloric acid ceases. The batch apparatus with nitrogen and the reaction mixture is heated is suctioned at room temperature (about 20 C.) and within about one hour to reflux temperature while stirring rinsed with anhydrous chlorobenzene and petroleum ether. After drying there are obtained about 118.6 parts of a yelit well, whereupon a strong evolution of hydrochloric acid sets in. After refluxing for 15 hours the evolution of hydrolow powder which melts at 330 C. with decomposition. chloric acid ceases substantially and the reaction product Crystallization from chlorobenzene furnishes the diforms a thick, yellow paste which is suctioned at room carboxylic acid chloride of the formula temperature and rinsed with xylene. The residue is then boiled with 5000 parts by volume of methanol, and dried, chloric acid, suctioned at room temperature and washed to yield about 577 partsot the compound of the formula with water until the washings run neutral.

(an I I I I I orr I as a yellow powder which meltsat 317 C. with decompo- 10 After two recrystallization-s from dimethylformamide sition. there are obtained about 14 parts of the compound of the 560 parts of the compound of the Formula 32 are formula t. (35) I .I

:oomorr omcmf HO o- CH=CH- 0 I O 4 .\O

stirredin 2000 parts by volume of phthalic acid dibutyl as a yellow powder melting above 310 C.

ester, and the reaction mixture is then heatedwith afree C H N O Calculated C, 73.11; H, 4.69; N, 5.02%. flame under nitrogen within 10 minutes-to 310 C., during Found C, 73.31; H, 4.85; N, 5.30%.

which water escapes and a dark solution forms which Exam 1e 7 is stirred for about 5 minutes at 310 to 320 C. and then p allowed to cool. At 100 c. 2000 parts by volume of 204 parts of powdered sti1bene-4,4'-dicarboXylic ac methanol are run into the thickly liquid suspension, which Chloride and 215 P of y yy i then suctioned at room temperatureand rinsed with ethyl-benzene are refluxed for 0 hours in 5 parts y methanol. The filter residue is extracted by being boiled volume of anhydrous xylene. The. thick suspension is then with 5000 parts of methanol, suctioned and thoroughly suctioned at r m temperature. thoroughly rinsed with rinsed with methanol and then crystallized from dimethylmethanol and sucked dry- The residue is Suspended in formamide, to yield about 302 parts of the compound of 1500 Parts y Volume of Phthalic acid diblltyl estel'find th f l the reaction mixture is heated with a free flame under O I I I o cornon I I CHCH:O CH c-orr=oH-Q oom l 1 I I I O 1 I i th for f ello prisms lti above 190 C, nitrogen to 310 C., whereupon water escapes and a dark C H N O Calculated C, 73.70; H, 5.15; N, 4.78%. solution forms which is stirred for about 5 minutes at Found'C, 73.77; H, 5.25;N, 5.02%. "310 to 320 C. and then allowed to cool. At 100 C. t 1 6 II 1000 parts of methanol are run into the thick suspension I I mP I which is then suctioned at room temperature and 147- parts of the compound of the Formula 33 are thoroughly rinsed with-methanol.

stirred 'in a solution of parts of sodium hydroxide in Crystallization from dimethylformamide furnishes 200 parts by volume of water and 1800 parts by volume about parts of the compoundof the formula (as) I of ethyleneglycol monomethyl ether for 1 hour "at" the refiux temperature, whereupon a thick suspension is in the form of yellow prisms. After further crystallization formed which is suctioned at room temperature and rinsed I from dimethylfor-mamide the compound melts above withmethanol. The residue is boiled with 2000 parts by 60 320 C.

volume of dimethylformamide, suctioned while still hot C H N O Calculated C, 78.44%; H, 4.65%; N and rinsed with methanol and dried, to yield about 10.76%. Found C, 78.43%; H, 4.80%; N, 10.68%. parts of the compound of the formula -o I I N o a0. 7 I ONa as a brilliant yellow powder which does not melt'below Example 8 350 C.

30 parts of the disodium salt of the Formula 34 are 10,000 parts of a polyamide in chip form, prepared in dissolved in 750 ,parts by volume of hot water; active the known. manner from hexamethylenediamine adipate, carbon is added;v and the whole is'filtered clear while s'till are mixed for 12 hours in a tumbler with 30 parts of hot and then rendered acid'to Congo red with hydro titanium dioxide (rutil modification) and 2 parts of the 15 compound of the Formula 18. The chips treated in this manner are then melted in a boiler, heated with oil or diphenyl vapour at 300 to 310 C. (after having displaced the atmospheric oxygen from it with superheated steam) and then stirred for half an hour. The melt is then expressed under a nitrogen pressure of atmospheres (gauge) through a spinneret and the resulting filament is allowed to cool and wound up on a spinning cop. The resulting filaments display an excellent brightening efiect which is stable to thermosetting and has good fastness to washing and light.

Example 9 100 parts of a polyester granulate from polyterephthalic acid ethyleneglycol ester are intimately mixed with 0.01 part of the compound of the Formula 18 and melted with stirring at 285 C. Spinning of this spinning composition through conventional spinnerets results in strongly brightened polyester fibers.

If desired, the compound of the Formula (18) may be added to the starting materials before or during the polycondensa-tion leading to the polyester.

Example Polyvinyl chloride fibers (registered trade mark Thermovyl) are treated for one hour at to C., at a goods-to-liquor ratio of 1:40, with 0.02% of the compound of the Formula 17 in a bath containing per liter 2 g. of an adduct from about 35 rnols of ethylene oxide with 1 mol of oetadecyl alcohol (dispersant). The fibers are then rinsed and dried.

1 6 Example 12 10,000 parts of a polyamide in chip form, prepared in the known manner from e-caprolactam, are mixed with 30 parts of titanium dioxide (rutil modification) and 2 parts of the compound of the Formula 18 for 12 hours in a tumbler. The chips treated in this manner are melted in a boiler from which the atmospheric oxygen has been displaced and which is heated at 270 C., and the melt is then stirred for half an hour, then expressed under a nitrogen pressure of 5 atmospheres (gauge) through a spinneret, allowed to cool and wound up on a spinning bobbin. The filaments obtained in this manner possess an excellent brightening effect which is stable to thermosetting and has good fastness to washing and light.

What is claimed is:

1. A bis-benzoxazolyI-stilbene of the formula wherein U represents a member selected from the group consisting of hydrogen and i the formula The polyvinyl chloride fibers treated in this manner possess a substantially higher white content than the untreated fiber.

Example 11 An intimate mixture of parts of polyvinyl chloride, 3 parts of stabilizer (Advastat BD 100; Ba/Cd complex), 2 parts of titanium dioxide, 59 parts by volume of dioctylphthalate and 0.01 to 0.2 part of the compound of the Formula 23 is rolled on a calender at to C. to form a foil. The resulting opaque polyvinyl chloride foil has a substantially higher white content than a foil that does not contain the bis-oxazolyl-stilbene compound.

wherein Y is a member selected from the group consisting of a carboxyl group, a carbalkoxy group having from 1 to 6 carbon atoms in the al-koxy group a carboxylic acid allyl ester group and a -COO-(C -C )alkylene-O-alkyl 1- 2) p- 4. The compound according to claim 1 of the formula 1 7 1 8 5. The compound according to claim 1 of the formula H30 0 0 CH3 H30 CH3 6. The compound according to claim 1 of the formula if -O(GHz)11OH 7. The compound according to claim 1 of the formula 8. The compound according to claim 1 of the formula N N i CH OCHzCHzO C c ocmcmoon, \O/ \O/ 9. The compound according to claim 1 of the formula 10. The compound according to claim 1 of the formula N N 01130 0 c-cHT-om- (whom-c 0 00113 Q- -Q 11. The compound according to claim 1 of the formula N N G zCHzCN 12. The compound according to claim 1 of the formula (3H1 N N CH3C References Cited UNITED STATES PATENTS 3,260,715 7/1966 Saunders 2-60240 JOHN D. RANDOLPH, Primary Examiner.

UNITED STATES PATENT ()FFICE CERTIFICATE OF CORRECTION Patent No. 3,407,196 October 22, 1968 Peter Liechti et a1.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 17, the left-hand portion of the formula in claim 12 should appear as shown below:

CH 3 N Signed and sealed this 10th day of March 1970.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting Officer Commissioner of Patents 

